The present invention relates to a wheel supporting rolling bearing unit.
As wheel supporting rolling bearing units, there exists a wheel supporting rolling bearing unit in which an inner race is fitted on an outer circumferential surface of an inner shaft at one end thereof and one end portion of the inner shaft is clamped against an outer end face of the inner race so as to fix the inner race to the inner shafts and a pulser ring is attached to the side of the inner race in such a manner as to face a magnetic sensor on the side of an outer race for detecting rotation (refer to Patent Document JP-A-2003-121454). The pulser ring is fitted in the shoulder portion of the inner race to thereby be fixed thereto in such a manner that a detecting portion thereof faces the magnetic sensor in the axial direction.
In the related rolling bearing units, since the position of the detecting portion of the pulser ring relative to the magnetic sensor, that is, the detection diameter of the detecting portion is determined by the outside diameter of the shoulder portion of the inner race, it is necessary to use an inner race that has a shoulder portion whose outside diameter satisfies the required detection diameter. Due to this, once there occurs a change in the detection diameter, the inner race needs to be changed to one having a shoulder portion whose outside diameter satisfies the changed detection diameter, this increasing the production costs of the rolling bearing units. In addition, when attempting to cut the outside diameter portion of the shoulder portion so as to make the outside diameter of the shoulder portion match the changed detection diameter, the cutting work has to involve some costs.